Press guard



March 9 1926. 1,575,843

. A. JONES PRESS GUARD Filed June l2, 1924 Patented Mar. 9, 1926.

UNITED STATES ALFRED JONES, 0F BIRMNGHAM, ENGLAND.

PRESS GUARD.

Application medium@ i2, 1924. seriai- No. 719,630.

'0 all whom it may @If-noemt:

Be it known' that Airman JONES, a subject of the King of Great Britain, residing at 15 Oxford Street, Birmingham, England, has invented a new and useful Improvement in or Connected with Press Guards; and he does hereby vdeclare the following to be a full, clear, and exact description of the same.

This invention has referencev to improvements in and connected with press guards for clutch controlled power presses and other machinery of a similar character, and has for its object to provide an eective but simple form of press guard which avoids any possibility of damage to the hands of thev operator or feeder to the press, the guard being readily adapted to and connected with power .presses or other machines of this character without involving any material alteration in the construction thereof.

Theinvention consists of the combination with a clutch controlled power press or machine of a like character of al guard which is characterized by the guard plate being independent yof the mechanism for operating the press, the guard being adapted for traversable motion across the frontof the press by the operator, the guard plate constituting a stop yor bar to a mechanism connectedV to the treadle or hand lever of the pressv when it is inany position other than that which the guard plate occupies when it has been completely traversed across the front of the press. The invention further resides in the provision `of a spring controlled meinber associated with the said guard plate in such a manner that should the ram or plunger of the press descend before the guard plate has been traversed completely across the front of the press the said spring controlled member is released by the downward motion of the ram or plunger and the guard plate is caused to travel rapidly across the front of the press and forcibly remove the operators hand from the danger zone.

The invention will now bedescribed with particular reference to the accompanying sheet of drawings, wherein: Y

Fig. 1 is a front elevation of a press guard constructed in accordance with the invention as applied to a power press, the guard being shown in the openv or retracted position. Y

Fig. 2 is a similar view to Figure 1 showing the vguard in the closed or projected position.

Fig. 3 is a in Figure 2.

Fig. l is an elevation -to an enlarged `scale of the automatic safety vrelease device, and.

Fig. 5 is a plan of part of Figure 1. The guardp'late which c( inprises a metal framework (i, having a wire mesh panel 7 is slidably mounted by means. ofits extendingV angle section upper side 6a within guide slots 8b formed in a member 8a secured to brackets 8 att-ached to the frame 9 of the press, a handle 10 secured to the member 6 affording a convenient means for effecting the traverse of the guard plate.

The lowering or raising of the plunger 11 onto or away from the work contained .in the die 12 is effected by means of a lever 13 pivotally mounted on an'ear 9a of the press frame 9 the leve-1118 having a kpin and slot connection with a rod 14 operating the 'clutch mechanism. Secured to the lever 13 isY a downwardly depending cranked `section 13a the lower end of which `when Vthe .guard is` inthe open or retracted posit-ion, seerFigure 1, contacts with the upper surface ofthe side 61L of the guard plate whereby the said `lever 13 is locked against operation when the guard plate is in the aforesaid position.

Attached to and moving with the yplunger 11 is a cranked rod 15 the lower end of which is adapted under circumstances to be hereinafter i described yto co-operat'e vwith a .camV shaped lever 16 pivotally secured to an yarm 17 in turn pivotally mounted on the member 8 by means of a stud 18 the pivotal `motions of the lever 16 and arm 17 taking place in planes at right angles Ito one another. Slidably mounted at the front of the press is a square rod 19 adapted to be controlled by a coil spring 20, the rod 19 passing through the vertical sides of the guard plate and the rod head 19a being adapted `to abut one side of the guard plate when the plate is in its open position as is seen in Figure 1. The other end of the rod 19 isfdisposed within a square slot 8C formed in the member ySathe end of the ,said rod normally abutting the arm 17 whereby the rod is maintained in its out lof action position and the spring 20 under tension. A spring 21 securedto the arm 17 and to a finger 8d securedto the bracket 8 normally maintain's'the arm 17 in its aforementioned locking position. Mounted on the extending top side 6a of the guard plateis a projection 22 adapted toV contact with'the 'cam lever 16 and to rock plan of the press gua-rd as 4seen this lever about its pivot and thereby remove it out of the path of the cranked rod 15 during the normal working of the press, a spring` Q3 secured tothe lever 16 and to the member 8a returning the lever 16 to its acting position upon the remo val of the projection 22.

The operation of the guard is as follows: When the guard plate is in the open or retracted position and access to the press is permissible, the lower end of the cranked extension 13a of the lever 13 contacts with the upper surface of the top side 6a and thereby renders the actuation of the lever 13 to effect a lowering of the plunger impossible as has hereinbefore been mentioned. Upon the operator desiring to work the press the guard plate is traversed along the face of the press until the whole of the side 6 has been removed from contact with the cranked extension 13a of the lever 13 in which condition access to the press `is prevented and the operation of the lever 13 per* mitted. It should be noted that this arrangement ensures that the press guard must be in its fully closed position before the lever 13 can be operated and the descent ofthe plunger 11 effected.

In the event of the clutch mechanism seizing while the guard is in the open position and the consequent descent of the plunger, the cranked rod 15 strikes the lever 16 and rocks the lever 16 and the arm 17 about the stud 18, thereby freeing the slot 8 from the obstruction of the arm 17, whereupon the rod 19 under the action of the spring 2O shoots across the face of the press and carries with it the press guard and thereby forcibly removes the hands of the operator from the danger zone. The rod 19 is reset by any convenient means for the subsequentV operation of the press, but in order to prevent the release of the safety device during the normal working of the press it is arranged that on the traverse of the guard plate to the closed position the projection 22 thereon moves the lever 16 out of the path of the cranked rod 15 and thereby prevents the release of the rod 19.

It will thus be observed that a press guard in accordance with this invention secures complete protection for the operator since in normal working the press cannot be operated until the guard is in its completely closed position, and should the mechanism foul through any cause and accidentallyset the press in operation the safety device ensures that the operators hands are removed from the press before the plunger descends on to the lower die.

Claims A 1. In a power press, the combination of a. lever for controlling the operation of the press, and a member adapted to be traversed across the front of the press to prevent access thereto, said member having a section thereof so disposed within the path of the actuating lever that the operation of the said lever is prevented unless the member is in its completely traversed position.

2. In a power press the combination of a lever for controlling the operation of the press, a member adapted to be traversed across the front of the press to preventaccess thereto and so related to said lever that the lever cannot be operated unless said member is in its fully closed position1 and means for freeing the front of the press from obstructions in the event of the accidental operation thereof due to mechanical derangement.

3. In combination with a power press having a frame, a plunger mounted in said frame and a fixed die; a lever for controlling the operation of said plunger, a guard adapted to be traversed across the front of the press to prevent access thereto said guard co-operating with said lever so that the lever cannot be operated unless the guard is in its fully closed position, means controlled by the plunger for forcibly removing the hands of the operator in the event of the accidental operation of the press, and means for rendering inactive the first mentioned means when the guard is in its closed position.

1. In combination with a power press having a frame, a plunger mounted in said frame and a fixed die; brackets secured to said frame, a guide member secured to said brackets, a. guard plate having one side thereof slidably mounted in said member, means for traversing said guard plate across the front of the press to prevent access thereto, a lever for controlling the operation of said plunger and co-operating with said plate whereby the lever cannot be operated unless the said plate is in its fully closed position, means controlled by said plunger for forcibly removing the hands of the operator in the event of the accidental operation of the press due to mechanical derangement, and means for rendering inactive the first mentioned means when the guard plate is in itsfully closed position.

5. In combination with a power press having a frame, a plunger mounted in said frame, and a fixed die; brackets secured to said frame, a slotted plate secured to said brackets, a guard plate having an extending side thereof slidably mounted in the slotted plate, a handle for traversing said guard plate across the front of the press to prevent access thereto, a lever for controlling the operation of the plunger and cooperating with the guard plate whereby the lever cannot be operated unless the guard plate is in its fully closed position, a cranked rod connected to said plunger, an arm pivoted to said slotted plate, a cam shaped lever pivotally mounted on said arm and having one end thereof disposed in the path of said rod, and a spring controlled yrod slidably mounted Within said slotted plate and controlled by said cam-shaped lever said rod being adapted to traverse the guard plate rapidly across the front of the press in the event of any operation thereof due to mechanical derangement and thereby to free the front of the press.

6. In combination With a power press having a frame, a plunger mounted in said fram-e, and a fixed die; brackets secured to said frame, a slotted plate secured to said brackets, a guard 'plate having an extending side thereof slidably mounted in the slotted plate, a handle for traversing said guard plate across the front of the press and thereby preventing access thereto, a lever for controlling the operation of said plunger and co-operating with the guard plate Whereby the lever cannot be operated unless the said guard plate is in its fully closed position, a cranked rod connected to said plunger, a spring controlled arm pivotally mounted on said slotted plate, a cam shaped lever pivotally mounted on said arm and having one end thereof disposed in the pathV ALFRED JoNns. 

